ZIP Code 20603 — Waldorf, MD
20603 is a standard (street delivery) ZIP code serving Waldorf, Maryland, in Charles County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 20603 at a glance
| ZIP code | 20603 |
|---|---|
| Primary city | Waldorf |
| State | Maryland (MD) |
| County | Charles FIPS 24017 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 31,844 |
| Coordinates | 38.629720, -76.974730 |
How ZIP+4 works in 20603
The four digits after the hyphen encode a delivery segment inside 20603. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 20603 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Other ZIP codes in Waldorf
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 20603.
| ZIP | City | Distance |
|---|---|---|
| 20695 | White Plains, MD | 2.8 mi |
| 20675 | Pomfret, MD | 3.9 mi |
| 20607 | Accokeek, MD | 4 mi |
| 20602 | Waldorf, MD | 5.4 mi |
| 20601 | Waldorf, MD | 6.4 mi |
| 20616 | Bryans Road, MD | 6.4 mi |
| 20646 | La Plata, MD | 7.6 mi |
| 22308 | Alexandria, VA | 8.2 mi |
| 20744 | Fort Washington, MD | 8.6 mi |
| 20617 | Bryantown, MD | 8.8 mi |
| 20735 | Clinton, MD | 9.1 mi |
| 22309 | Alexandria, VA | 9.4 mi |
Questions about 20603
What is the ZIP+4 code for 20603?
20603 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 20603, you need to look up a specific street address to get them.
What city is 20603?
20603 is assigned to Waldorf, Maryland, in Charles County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.